Basic welding powders



United States Patent O 3,211,591 BASIC WELDING POWDERS GustavMiitschitzky and Walter Schindelin, Burghausen, Upper Bavaria, Germany,assignors to Wacker-Chemie G.m.b.H., Munich, Germany, a corporation ofGermany N Drawing. Filed Oct. 30, 1961, Ser. No. 148,699 Claimspriority, application Germany, Sept. 26, 1958, W 24,165 8 Claims. (Cl.148-26) This application is a continuation-in-part of our applicationSerial No. 839,996, filed September 15, 1959, now abandoned, for BasicWelding Powders.

This invention relates to basic welding powders and it has for itsobject to provide novel and improved powders of this type.

Another object of the invention is to increase the tensile strength,impact resistance and bending resistance of seams which are welded withwelding powders.

Still another object is to provide welding powders for welding unalloyedas well as alloy steel, in which the known prior art ingredients ofconventional welding powders are proportioned and mixed in a novelmanner which materially increases the effectiveness of the weld.

Other objects and advantages will be apparent as the nature of theinvention is more fully disclosed.

The requirements for the mechanical strength values of welded seams aresteadily increasing. Besides good tensile strength, the values forimpact resistance should approximate those of the basic material asclosely as possible. Hence up to now it has been considered a deficiencywhen the impact and bending resistance of seams welded with weldingpowders did not satisfy higher requirements.

The reason for the unsatisfactory welding results to date might beascribed to the fact that the significance of the mole proportions ofthe individual components of the welding powders, in their relationshipto each other, has so far not been recognized.

We have discovered a way of making basic welding powders which can beused for welding unalloyed as well as alloy steel, where the alreadyknown components of usual welding powders are added in such a way thatthe basic proportion is 1.1-2.2 and the mole proportions are: MnO:SiO:1.0-2.2, preferably 1.151.7,

preferably 2.03.0, CaO:MgO:l.2-1.8, preferably, 1.2 1.6, whereupon themixture is subsequently melted down, sintered and agglomerated. Thebasicity proportion is understood to be the mole proportion(CaO-i-MgO-l-alkaline oxide) :SiO

The basic substances usually forming welding powders are silicic acid,alumina, titanium oxide, calcuim oxide, magnesium oxide, manganeseoxides, fluorspar and alkaline oxides. Besides these components, suchelements, alloys, compounds (for instance oxides, silicides, carbides,nitrides, borides) and mixtures of these substances can be added to thewelding powder, which are contained in the material to be welded orwhich are to be alloyed into the work material. The addition of suchsubstances serves to preserve the composition of the work materialsused, or it is useful for their improvement. From the great number ofsubstances that can be used, the follow ing are mentioned by way ofexample: copper, boron, zirconium, vanadium, niobium, tantalum,chromium, molybdenum, tungsten, uranium, cobalt, nickel, carbon and rareearths. By adding these substances a refinement of the texture can beachieved for instance, also increased corrosion resistance and animprovement of the mechanical characteristics of the weld.

The substances can be mixed and subsequently processed by melting,sintering or agglomeration and granulated afterwards. But it is alsopossible to mix the elements, compounds or alloys in powder formseparately or mixed together-with the welding material that has been premelted, pre sintered or agglomerated and crushed again, and to subjectit to a process of sintering once more. If the substances which might benecessary for the agglomeration are not contained in sufficient quantityin 'the'original mixture, they can be added later. If necessary, thiscan be done in an inert or' reducing atmosphere, whichever may berequired.

The welding powder obtained can be used for the under-powder process,for the electric slag welding process and also for the inlay process.

The following examples give compositions which were melted and testedfor their welding characteristics, these being given both with andwithout the addition of the steel-refining component which is containedin the work material to be Welded. In Example 1 said component is NiO,in Example 2, V 0 in Example 3, Cr 0 In Examples 4, 5 and 6 it is awelding powder containing Mo, W and Zr, respectively. All figures are inweight percent.

These two welding powders have a basicity ratio of 1.33; the mole ratiosare MnO:SiO =1.2;

EXAMPLE 2 Without With Vanadium Vanadium Oxide, Oxid percent percentSl-O2 18. 7 18.7 A1201 15. 3 15. 3 TiOL 3. 9 3. 9 MnO 28. 7 28. 7 C2014. 9 14. Q MgO. 7. 5 7. 5 OaF-i 11. 0 10. 5 V205. 0. 5

The basicity ratio: 1.45; the mole ratios are MnO :SiO =1.3; A1 0 :TiO=3.0; CaO MgO= 1.43.

EXAMPLE 3 Without With Chromium Chromium Oxide, Oxide, percent percentSiOL 14. 83 14.17 A1201 23. 16 22. 05 T10; 7. 89 7. 53 MnO 21. 77 20.(38.0 13.47 12. MgO 7. 25 6. 92 CaF, 10.43 10.01 K20 1. 20 1. 13 011034. 59

The basicity ratio::1.75; the mole ratios are MnO:SiO :l.24; A1 O :TiO=2.3; CaO:MgO:1.75.

EXAMPLE 4 The basicity ratio=1.27; the mole ratios are MnO:SiO =1.157;Al O :TiO :2.09; CaO:MgO:1.408.

EXAMPLE 5 Welding powder containing tungsten Percent SiO 17.96 A1 16.07TiO 4.13 MnO 25.14 0210 9.82 MgO 5.79 $8 2'23 CaF 14.55

The basicity ratio:1.187; the mole ratios are MnO:SiO =1.18; Al O :TiO=3.06; CaO:MgO 1.22.

EXAMPLE 6 Welding powder containing zirconium Percent SiO 15.05 A1 012.85 ifs '22 11 ZrO 12.30 CaO 9.66 1 2'23 2 CaF 16.80

The basicity ratio:1.242; the mole ratios are MnO:SiO :1.277; Al O :TiO:2.65; CaO:MgO:1.55.

During the welding tests all powders tested in accordance with theunderpowder-process and even welding, yielded uniform convex, smoothseams without any edge notches. None of these powders shows any tendencyto crack or to form pores. The slag easily separates from the coolingseam. a jj j' Compared with those of normal weldings, the picture ofpolished sections shows an extraordinarily fine texture which is onlyslightly distinguishable from the'working material. 1

The impact resistance figures show values of up to 14.3 m-kg./cm. TheBrinell hardnessoftheworking material varies between 122-125, that ofthe welding transitions between 140-158 and that of the center of theweld between 165-172.

The invention claimed .is:

1. A basic welding powder for welding iunalloyed andalloyed steel,consistingessentially of MnO, SiO A1 0 TiO CaO, and MgQ, said componentsbeing 7 compounded in such proportions that the ratio ofbasicity is1:1-2:2 and the mole pratios are 1 {InO: SiO 1-2.2, Al O :TiO 1.5,CaOzMgO: 1.2-1.8.

2. A basic welding powder for welding 'unalloyed and alloyed steel,consisting essentially of MnO, SiO A1 0 TiO CaO, and MgO, saidcomponents being compounded in such proportions that the ratio ofbasicity is 1:1-2:2 and the mole ratios are MnO:SiO =1.15-1.7, Al O :TiO=2.O-3.O, CaO:MgO=1.2-1.6.

3. Welding powders according to claim 1, consisting essentially of:

21.23-21.60 weight percent SiO 10.03-10.20 weight percent A1 0 3.94-4.00Weight percent TiO 30.20-30.70 weight percent MnO 15.75-16.00 weightpercent CaO 7.55-7.70 weight percent MgO 9.65-9.80 weight percent CaF upto 1.65 weight percent NiO balance incidental impurities.

4. Welding powders according to claim 1, consisting essentially of:

18.7 weight percent Si0 15.3 weight percent A1 0 3.9 weight percent TiO28.7 weight percent MnO 14.9 weight percent CaO 7.5 weight percent MgO10.5-11.0 weight percent CaF up to 0.5 weight percent V 0 balanceincidental impurities.

5. Welding powders according to claim 1, consisting essentially of14.17-14.83 weight percent S10 22.05-23.16 weight percent A1 0 7.53-7.89weight percent Ti0 20.75-21.77 weight percent M 12.85-13.47 weightpercent CaO 6.92-7.25 weight percent MgO 10.01-10.43 weight percent CaF1.13-1.20 weight percent K 0 up to 4.59 weight percent Cr O balanceincidental impurities.

6. A welding powder according to claim 1, consisting essentially of: i

14.20 weight percent SiO 23.10 weight percent A1 0 8.65 weight percentTi0 19.40 weight percent MnO 9.10 weight percent CaO 4.85 weight percentMgQ 2.20 weight percent K 0 1.40 weight percent M110 v 17.10 Weightpercent CaF balance incidental impurities.

' 7. A welding powder according to claim 1, consisting essentially of:

17.96 weight percent SiO 16.07 weight percent A1 0 4.13 weight percent TiO 25.04 weight percent MnO 9.82 weight percent CaO 5.79 weight percentMgO 3.44 weight percent K 0 3.20 Weight percent W0 14.55 weight percentCaF balance incidental impurities.

8. A welding powder according to claim 1, consisting essentially of:

15.05 weight percent S10 12.85 weight percent A1 0 3.80 Weight percentTiO 22.66 weight percent MnO 12.30 Weight percent ZrO 5 6 9.66 Weightpercent CaO 2,751,478 6/56 Jackson et a1 148-26 X 4.48 weight percentMgO 3,023,133 2/62 Lewis et a1 148-26 2.40 Weight percent K 0 16-80Weight Percent z DAVID L. RECK, Primary Examiner. balance incidentalimpurities. 5

References Cited by the Examiner UNITED STATES PATENTS 2,043,960 6/36Jones et a1 148-26 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIONEetent No 3 211 591 October 12 1965 Gustav Miltschitzky et al It ishereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 3, line 74, for "1.5," read 1.5-3.5,

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNE] Attesting Officer Commissioner ofPatents

1. A BASIC WELDING POWDER FOR WELDING UNALLOYED AND ALLOYED STEEL,CONSISTING ESSENTIALLY OF MNO, SIO2, AL2O3, TIO2, CAO, AND MGO, SAIDCOMPONENTS BEING COMPOUNDED IN SUCH PROPORTIONS THAT THE RATIO OFBASICITY IS 1:1-2:2 AND THE MOLE RATIOS ARE MNO:SIO2=1-2.2,AL2O3:TIO2=1.5, CAO:MGO=1.2-1.8.